1. Field of the Invention
The present invention relates to a multiple magnetic pump system in which driving force is magnetically transmitted to an impeller.
2. Description of the Related Art
FIGS. 1 and 2 show in combination a conventional magnetic pump 10, disclosed in, for example, Japanese Utility Model Publication No. 20340/1970, which is employed to pump a processing liquid used in a photographic developing apparatus.
The pump 10 is arranged such that a driving magnetic material 16 which is secured to a driving shaft 14 of a motor 12 rotates around the outer periphery of a partition tubular member 15 provided in a casing 26 to drive a driven magnetic material member 20 buried in an impeller 18 located in a pump chamber 17 so that the impeller 18 is rotated. A lubricating member 19 which also serves as a spacer is disposed between the outer periphery of the impeller 18 at which the driven magnetic material member 20 is positioned and the inner periphery of the tubular member 15 for the purpose of enabling the impeller 18 to rotate smoothly. The rotation of the impeller 18 causes a processing liquid to be sucked in from an inlet port 22 provided on the prolongation of the axis of the driving shaft 14, the processing liquid then being discharged from an outlet port 24 by means of centrifugal force.
In the pump 10 having such a structure, the motor 12 and the pump chamber 17 are shut off from each other by the tubular member 15 provided in the casing 26 so that no processing liquid in the pump chamber 17 leaks out.
Since a photographic developing apparatus is generally provided with a plurality of processing tanks for containing, for example, a developer, a fixer, water for rinsing and so forth, it is necessasry to provide a number of pumps 10 corresponding to the number of the processing tanks. In the pump 10 with the above-described structure, however, the inlet port 22 is provided on the prolongation of the axis of the driving shaft 14 of the motor 12, and this permits only one pump 10 to be provided for a single motor 12. Accordingly, it is necessary to provide a number of motors 12 corresponding to the number of required pumps 10.